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21.
This article describes a process for competency interviewing of staff nurse applicants based on an evaluation of their knowledge, skills, and abilities. Planning an interview with consideration of job requirements and organizational expectations is essential. Guidelines for developing interview tools, conducting the interview, and rating applicants are included. 相似文献
22.
Sandra E. File T. A. James N. K. MacLeod 《Journal of neural transmission (Vienna, Austria : 1996)》1981,50(1):1-12
Summary 5, 7-Dihydroxytryptamine (10 and 20g) was microinjected bilaterally into the amygdaloid complex of rats and resulted in 55% and 80% depletion in 5-hydroxytryptamine concentration, respectively. The lesioned animals exhibited fewer dominance behaviours and submitted more often to an intruder into their home-cages than did the vehicle-injected controls. The lesioned rats were also more submissive than were the controls when they were intruding into another rat's territory. Only the higher dose of toxin altered social investigatory behaviour when this was measured in an arena in which neither rat had established territory. The lesioned rats displayed less social interaction and had reduced levels of motor activity. The results are compared with those of other studies in which there has been regional or general depletion of brain 5-hydroxytryptamine concentration. 相似文献
23.
Covalent binding of isomeric benzo[a]pyrene diol-epoxides to DNA 总被引:1,自引:0,他引:1
We have compared the abilities of two diol-epoxide derivativesof benzo[a]pyrene (B[a]P) to bind covalently to DNA in a simplein vitro system. Purified DNA in aqueous solution was allowedto react with (±)-7, 8ß-dihydroxy-9ß,10ß-oxy-7,8,9,10-tetrahydroB[a]P (BPDE) or with (±)-9,10ß-dihydroxy-7,8-oxy-7,8,9,10-tetrahydroB[a]P (reverseBPDE) to completion. After repurification of the DNA, bindingwas detected by fluorescence spectroscopy or by absorbance spectroscopy.Both BPDE and reverse BPDE but not their hydrolysis productsexhibited binding which increased linearly with increasing diolepoxide concentration. When DNA modified by reverse BPDE wasenzymatically hydrolysed, two major fluorescent deoxyribonucleoside-adductswere detected by reverse phase h.p.l.c. These were separablefrom the major adduct obtained from BPDE-modified DNA and fromthe major products obtained by hydrolysis of reverse BPDE inthe absence of DNA. Absorbance and fluorescence spectroscopyof modified native DNA suggested that the pyrene nucleus ofreverse BPDE but not of BPDE was intercalated in the DNA doublehelix. This suggestion was supported by fluorescence-quenchingstudies. In the presence of increasing DNA concentrations, covalentbinding of both diol epoxides increased towards an apparentmaximum. Double reciprocal analysis of the data indicated amaximum binding level of 5% of the total dose for BPDE and 4%for reverse BPDE. This suggests that for both diol epoxidesthe ratio of the rate constants for covalent binding and forDNA-enhanced hydrolysis are nearly the same. Covalent bindingof reverse BPDE to DNA was effectively blocked by low concentrationsof Mg2+, suggesting that formation of a non-covalent intercalationcomplex may be a prerequisite for covalent reaction. 相似文献
24.
25.
Human leukemia-lymphoma (LL) cell lines represent an extremely important resource for research in a variety of fields and disciplines. As the cell lines are used as in vitro model systems in lieu of primary cell material, it is crucial that the cells in the culture flasks faithfully correspond to the purported objects of study. Obviously, proper authentication of cell line derivation and precise characterization are indispensable requirements to use as model systems. A number of studies has shown an unacceptable level of LL cell lines to be false. We present here the results of authenticating a comprehensively large sample (n = 550) of LL cell lines mainly by DNA fingerprinting and cytogenetic evaluation. Surprisingly, near-identical incidences (ca 15%) of false cell lines were observed among cell lines obtained directly from original investigators (59/395: 14.9%) and from secondary sources (23/155: 14.8%) implying that most cross-contamination is perpetrated by originators, presumably during establishment. By comparing our data with those published, we were further able to subclassify the false cell lines as (1) virtual: cross-contaminated with and unretrievably overgrown by other cell lines during initiation, never enjoying independent existence; (2) misidentified: cross-contaminated subsequent to establishment so that an original prototype may still exist; or (3) misclassified: unwittingly established from an unintended (often normal) cell type. Prolific classic leukemia cell lines were found to account for the majority of cross-contaminations, eg CCRF-CEM, HL-60, JURKAT, K-562 and U-937. We discuss the impact of cross-contaminations on scientific research, the reluctance of scientists to address the problem, and consider possible solutions. These findings provide a rationale for mandating the procurement of reputably sourced LL cell lines and their regular authentication thereafter. 相似文献
26.
Abstract: We report the first case of fatal anthrax meningoencephalitis in Hong Kong over the past 60 years. A 13 year-old boy presented with right lower quadrant pain, diarrhoea and progressive headache. Lumbar puncture yielded gram positive bacilli initially thought to be Bacillus cereus, a contaminant. He was treated with ampicillin and cefotaxime, but died 3 days after hospitalization. The organism isolated from blood and cerebrospinal fluid was later identified as Bacillus anthracis. 相似文献
27.
A prospective study of methylenetetrahydrofolate reductase and methionine synthase gene polymorphisms, and risk of colorectal adenoma 总被引:8,自引:2,他引:8
Chen J; Giovannucci E; Hankinson SE; Ma J; Willett WC; Spiegelman D; Kelsey KT; Hunter DJ 《Carcinogenesis》1998,19(12):2129-2132
We examined the relationship between a functional polymorphism (667C--
>T, ala-->val) of the methylenetetrahydrofolate reductase gene
(MTHFR) and the risk of colorectal adenomas in the prospective Nurses'
Health Study. Among 257 incident polyp cases and 713 controls, the MTHFR
val/val polymorphism [relative risk (RR) = 1.35, 95% confidence interval
(CI) 0.84-2.17] was not significantly associated with risk of adenomas.
This lack of association was observed for both small (RR = 1.36, 95% CI
0.76-2.45) and large (RR = 1.32, 95% CI 0.66-2.66) adenomas. Furthermore,
there was no significant interaction between this polymorphism and
consumption of either folate, methionine or alcohol. We also examined the
relationship of a newly identified polymorphism (asp919gly) of the
methionine synthase gene (MS) with the risk of colorectal adenomas in the
same population. The MS gly/gly polymorphism was also not significantly
associated with risk of colorectal adenomas (RR = 0.66, 95% CI 0.26-1.70).
These results, which need to be confirmed in other studies, suggest that
the MTHFR val/val polymorphism, which has been previously inversely
associated with risk of colorectal cancer, plays a role only in a late
stage (adenoma-- >carcinoma) of colorectal tumorigenesis, and/or may
protect against malignant transformation in the subset of benign adenomas,
which may progress to malignancy.
相似文献
28.
OBJECTIVE: To examine national trends in mortality rates for injuries among Canadian children younger than 15 years in 1979-2002. METHODS: Data on injury deaths were obtained from the Canadian Vital Statistics system at Statistics Canada. Injuries were classified using the codes for external cause of injury and poisoning (E-codes) by intent and by mechanism. Mortality rates were age adjusted to the 1990 world standard population. Negative binomial regression was used to estimate the secular trends. RESULTS: Annual mortality rates for total and unintentional injuries declined substantially (from 23.8 and 21.7 in 1979 to 7.2 and 5.8 in 2002, respectively), whereas suicide deaths among children aged 10-14 showed an increasing trend. All Canadian provinces and territories showed a decreasing trend in mortality rates of total injuries. Motor vehicle related injuries were the most common cause of injury deaths (accounted for an average of 36.4% of total injury deaths), followed by suffocation (14.3%), drowning (13.5%), and burning (11.1%); however, suffocation was the leading cause for infants. The number of potential years of life lost due to injury before age 75 decreased from 89 343 in 1979 to 27 948 in 2002 for children aged 0-14 years. CONCLUSIONS: During the period 1979-2002, there were dramatic decreases in childhood mortality for total injuries and unintentional injuries as well as various degrees of reduction for all causes of injury except suffocation in children aged 10-14 years and drowning in infants. The reason for the reduction in injury mortality might be multifactoral. 相似文献
29.
Ratnayake R Karunaratne V Ratnayake Bandara BM Kumar V MacLeod JK Simmonds P 《Journal of natural products》2001,64(3):376-378
The structures of the butenolides 1 and 2, isolated from the endemic plants Hortonia floribunda, H. angustifolia, and H. ovalifolia, collected in Sri Lanka, have been elucidated by spectroscopic analysis. These compounds exhibited potent mosquito larvicidal activity against the second instar larvae of Aedes aegypti. 相似文献
30.
背景和目的:罗格列酮与阿伐他汀联合疗法已经被证实对于2型糖尿病患者的血糖控制以及脂质水平都有益处。本试验将通过检测罗格列酮与阿伐他汀联合疗法对于2型糖尿病患者的生物标记水平的作用来研究该联合疗法对血管炎的作用。方法:30例患有2型糖尿病和高脂血症的患者被纳入治疗。对这些患者给予罗格列酮单一疗法4mg/d,持续3个月,然后在接下来的3个月中给予这些患者阿伐他汀10mg/d作为联合疗法。在研究开始时,罗格列酮单一疗法之后以及罗格列酮与阿伐他汀联合治疗之后测量炎性生物标记物,包括高敏C-反应蛋白(hs-CRP)、基质金属蛋白酶9(MMP… 相似文献